Control apparatus



Nov. 11, 1941 w. v. HOBBS ETAL CONTROL APPARATUS Filed A ril 13, 19:59

2 Sheets- Sheet 1 24 r 2s 2 65 7s 23 i! 66 4 707 75 68 7247 '1 1 so 52 1 I as 55 so 77 .2

ATTORNEY Nov. 11, 1941. w. v. HOBBS ETAL 2,262,496

CONTROL APFARATUS Filed April 13, 1959 k 2 sheets-sheet 2 .IZM

ATTORNEY J Patented Nov. "11, 1941 CONTROL APPARATUS Walter V: Hobbs and Eldon D. Raney, Columbus, Ohio, assignors to Ranco Incorporated, Columbus, Ohio, a corporation of Ohio Application April 13, 1939, Serial No. 267,719

3 Claims.

The present invention relates tothermostatic control apparatus and more particularly to apparatus for controlling the air temperature of an enclosure. The subject matter of the present invention is related to the subject matter disclosed in the application of Eldon D. Raney,

- Serial Number 204,823, filed April 28, 1938, for

Control apparatus.

One of the objects'of the invention is to provide a control apparatus for a heat exchanger, which apparatus includes a temperature responsive device that is affected by the temperature of airdirectly from heat exchange relation with the heat exchanger and air unaffected by the heat exchanger so that th control apparatus will control the exchanger in accordance with the temperature of the air that is to be affected by the exchangerl Another object of the invention is to provide to afiect the temperature of the air flowing into an enclosure, which controller has a temperature responsive part thereof positioned in heat transfer relation with the heat exchanger and also in heat transfer relation with the air from the outside of the enclosure unaffected by the heat exchanger,

Other and further objects and advantages wfll be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiment of the presentinvention are clearly shown.

In the drawings:

Fig. 1 is a fragmentary side view of an automobile, partly in section, showing one form of the invention apphed to the heating system in a vehicle;

Fig. 2 is a fragmentary side view of an automobile, partly in section, showing another form of the invention applied to a heating system for a vehicle, and

Fig.3 is a fragmentary side view of the thermostatic system partly in section.

Referring to the drawings an automobile ll, having an enclosed passenger compartment ll,

is provided with an opening l2 at the front of the. compartment. ,The opening I! is adapted to beclosed by a cover l3 that is mounted on' suitable well known mechanism (not shown) that permits the cover l3 to be tilted to an open position, as illustrated in the drawings, by the operatorof the automobile. When the cover is in the open position. and the automobile is in motion, air will be deflected by. the cover into the the opening l2. The incoming air creates a pressure inside the compartment causing the air to leak outwardly through openings and crevices therein, and this fresh air entirely fills the com;- partment.

It is desirable to condition the air entering the compartment ll, so that the temperature thereof will be comfortable to the passengers in the automobile- The present invention provides means for conditioning the incoming air to maintain the interior of the compartment at a substantially uniform, comfortable temperature regardless of the changes in temperature of the outside air below the temperature desired to be maintained inside the automobile. In carrying out the invention a heat exchanger 26 is mounted in an inlet duct 2| that is connected with the opening it. The duct 2| is formed by a front wall 22 of the compartment II, a confronting -a control for a heat exchanger that is adapted wall 23 and two side walls 24 (only one appearing in the drawings). The walls 23 and 24 are attached to the top wall 25 of the compartment and extend downwardly somewhat below the bot tom of the exchanger 20. but terminate a sub- 25 stantiai distance from the floor of the compart ment to allow room for the legs of the persons riding in the front seat of the automobile. The wall 23 is provided with an offset section 26 to which one side of the exchanger 26 is attached.

'30 An electric powered fan 28, connected with the battery of the automobile, is mounted in the duct andoperates to direct air through the exchanger when the automobile is stationary.

The exchanger 20 may be of any suitable construction, but in the present embodiment, the

zontal planes and spaced from one another to "permit passage of air therebetween. Preferably tubes in difierent planes are staggered with respect to tubes in an adjacent plane so that substantially all of the air forced through the exchanger will-strikesome of the tubes.

One end of the tubes 36 in the upper section of the exchanger "are connected to a header 3| and the other ends thereof are connected to a common'header 32. The tubes 30 in the lower section of the exchanger are connected at one end of thevcoin'mon header 32 and the other ends thereof are connected to a header 33. The

headers 3| and 33 are suitably attached to the front wall 22 and side walls 24, and the header interior of the passenger compartment through 56 32 is attached to the walls 23 and 24. The header 3| is provided with an inlet 34 for receiving heated cooling medium from the water jacket of the automobile engine (not shown) through a tube 35. The header 33 is provided with an outlet 36 for discharging the heating medium after it has passed through the exchanger. A tube 31 connects the outlet 36 with a controller valve 40 that controls the flow of the medium through the exchanger. Thus heated liquid from the engine cooling system enters the header 3|, flows through the tubes in the upper section of the exchanger to the header 32 and then through the lower tubes 3|] to the header 33 and the tube 31 to the controller valve 40.

The controller valve includes a U shaped frame 4| having side walls 42 and 43 of triangular configuration. The side walls 42 and 43 are provided with outturned flanges 44 to which a valve casing 46 and a thermostatic system 41 are attached. The valve casing 46 is formed with an inlet 50, a valve seat 5|, an outlet 52 and a base 53 that is attached to the frame. The tube 31 is connected to the inlet and a tube 55 connects the outlet 52 with the water pump for the engine cooling system. A valve stem 54 extends into the valve casing and a suitable hermetic seal is provided between the stem and casing to prevent leakage of liquid around the stem. A valve plate 56 is attached to one end of the stem, and is adapted to close the valve seat 5|. The outer end of the stem 54 is attached to a channel shaped lever 60 pivoted between the walls of the frame by a pin 6|. The lever 60 is rocked about the pin 6| to open and close the valve by a compression spring 64 and the thermostatic system 41. The spring 64 is compressed between the lever 60 and a plate 65 and biases the lever 60 clockwise to open the valve. The plate 65 is threaded on a screw 66 rotatably mounted on the yoke 67 of the frame 4| and abuts the side walls of the frame to prevent rotation thereof so that the plate will be.

moved along the screw 66 when the screw is rotated. A knob 68 is attached at one end of the screw whereby the tension of the spring 64 may be adjusted by the operator of the automobile.

The thermostatic system 41 comprises a casing 10 having one end thereof closed by a bellows H, and a tube 15, closed at one end, connected with the enclosure formed by the bellows and casing. The casing is suitably attached to the flanges 44 of the frame 4|. The bellows II has one end open, and is closed at the other end by a wall 12. The edges at the open end of the bellows arehermetically joined to the walls of the casing as by solder. A pin 13 connects the end wall 12 with the lever 60. ,When the bellows H is collapsed by pressure within the casing 10, the lever 60 will be moved counterclockwise to close the .valve, and when the pressure within the casing is lowered, the spring 64 reacts against the let er 60 rotating it clockwise against the bellows to open the valve. The casing and the tube contain a volatile fiuid for example, methyl chloride or sulphur dioxide, the amount 'of fluid being such that the fluid will be completely vaporized at 90 deg. F. and below that temperature liquid fluid will be present in the system. The spring 64 is normally adjusted to commence to open the valve when the pressure in the thermostatic system 4! falls to a point corresponding. to the vapor pressure of the fluid open if any part of the system 41 is at '70 deg. F. or less. The amount of liquid in the system at temperatures below 70 deg. F. may be retained in a relatively short section of the tube by capillary attraction. Sections of the tube may be coiled to provide a condenser portion thereof that may be placed in an area, the temperature of which is to be a function of the valve.

Preferably the controller valve 40 is attached to the dash board of the automobile so that the knob 68 may be accessiblefor adjustment of the valve.

Referring to Fig. 1, an air by-pass tube extends along the outside of the air duct 2|, its upper end extending into the duct above the exchanger 20 and its lower end turned and extending through an opening in the wall 26 into the duct below the air discharge of the exchanger. The thermostatic tube 15 extends into the duct 2| through suitable openings in the wall 26.

The tube 15 is coiled at 16 and the coil is fitted inside a collar 8|, preferably formed of a heat conducting material, mounted on the end of the tube 80. The collar 8| is slotted at 82 to accommodate the thermostatic tube 15. Thus the outer surface of the coil 76 is subjected to heat of the air emanating from the heater and the inside of the coil will be cooled by air from the outside of the automobile compartment not affected by the exchanger.

A coil 11 is formed on the end of the thermostatic tube and this coil is located in the automobile compartment at a position where it will.

be responsive to a representative average temperature of the air in the compartment and where it will be colder than the other parts of the thermostatic system, except the coil 16, and at times may be colder than the coil 16.

Assuming that the controller 40 is adjusted to maintain a temperature of 70 deg. F. and that the temperature of the compartment and atmosphere are considerably below 70 deg. F., when the fan 28 is operating or the automobile is moving, and the cover I3 is open, air is directed from outside the automobile into the duct 2|, through the exchanger 2|] and out the lower end of the duct into the compartment The fluid in the thermostatic system 41 will be partly liquid and the pressure in the system will be relatively low so that the valve 40 will be opened by the spring in the system at 70 deg. F. Thus the valve will 64. Hot liquid from the engine will then flow through the exchanger and impart heat to the air passing therethrough. Heated air emanating from the exchanger strikes the collar 8| *and tends to warm the coil 16. Air from the outside, unaffected by the exchanger, passes through the tube 80 and tends to cool the inside of the coil 16 so that the temperature of the fluid in the coil 16 will be between the temperature of the unheated air and the heated air. Thus the outside air tends to lower the temperature of the coil 16. When the temperature of one of the coils rises while the other coil is below 70 deg. F.,

the valve will be controlled by the cooler of the coils since the liquid in the system will condense in that coil. For example, if the temperature of the coil 16, is raised above 70 deg. F. but the temperature of coil 11 is below 70 deg. F., the valve will not be closed until the temperature of the coil 1'! is raised to or above 70 deg. F. The valve is closed by increasing pressure in the hermostatic system caused by the. vaporization of the liquid fluid. The valve will bemoved toward open wide position when either one of the coils'16 or 1! falls below 70 deg. F.

The introduction of unheated air in heat trans-,v

fer relation with the coil "will cause the coil to be more readily cooled when the atmospheric temperature is relatively low. This insures that there will always be a warm flow of air through the heater to prevent chilling drafts of air over 6 the persons seated in the front of the automobile body" Also the heater will be caused to operate at higher temperatures in response to decreases in the atmospheric temperature thus automatically compensating for the increased heat 10 losses that will occur through the body of the automolziile The valve ell may be controlled solely according to the temperature or the coil 16 by omitting,"

the coil ill! and the portion of thetube l5 connectit ing the coils.

Referring to 2, another arrangement for controlling the operation of the thermostatic system is shown In this embodiment of the invention, a tube 85 is provided having two 20 branching sections ht and B1. The section 86 extends outside the duct wall 26 and upwardly into the upper part of the duct 2| above the exchanger. The section it? extends upwardly,

terminating adjacent the air outlet of the ex- 5 changer. The end of the thermostatic tubeis coiled at fill and is disposed in the tube 85 adjacent the outlet thereof. Thus a mixture of heated and unheated air will strike the coil 88 to affect the temperature of the coil. ltisi' apparent that so second cell at the end thereof and disposing that 40 cell in the automobile passenger compartment.

While the terms of embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of portion being disposed to be more directly the claims which follow.

We claim: 1. In combination, means forming an inclosure for air; a heat interchanger associated with the inclosure; means for directing air over the in- '50 terchanger for affecting the temperature in the inclosure; means operable for attaining a desired temperature or air within the inclosure and operable after said desired temperature is at tained, for preventing the temperature of the air emanating from the heat intercha'nger from varying beyond a certain temperature, said last means including a controller for changing the rate of heat exchange between the heat int'erchangar and theair, and a pressure responsive device for 0 partially liquid and partially vapor when the heat exchange system is operating normally, said condensing means having a plurality oi condenser portlonsspaced from one another, the relative amounts of liquid and its. vapor being so proportioned that substantially all of said liquid is adapted to be contained in one or the other of said condenser portions whereby the controller is responsive substantially solely to the temperature of the colder condenser portion, one of said condenser portions being disposed to be affected by the temperature of the air in the inclosure remote from the heat interchanger and the other condenser portion being disposed to be more directly affected by the temperature of the air subjected to the heat interchanger; and means for bypassing air around the interchanger and into heat exchange relation with the-last mentioned condenser portion.

2. In combination, means forming an inclosure for air; a heater associated with the inclosure; means for directing air over the heater for afiecting the temperature in the inclosure; means operable for maintaining at least a predetermined minimum temperature of air within the inclosure and operable, after said predetermined temperature is attained, for preventing the temperature of the air emanating from the heater from falling below a certain temperature, said last means including a controller for changing the rate of heat exchange between the heater and the air, and a pressure responsive device for regulating the controller, said pressure responsive device having condensing means connected therewith, said device and condensing means containing a heat responsive fluid, sai fluid being partially liquid and partially vapor when the heat exchange system is operating normally, said condensing means having a plurality of condenser portions spaced from one another, the relative amounts of liquid and its vapor being so proportloned that substantially all of said liquid is adapted to be contained in one or the other or said condenser portions whereby the controller is responsive substantially solely to the temperature of the colder condenser portion, one of said condenser portions being disposed to be affected by the temperature of the air in the inclosure remote from the heater and the other condenser affected by the temperature of the air subjected to the heater; and means for by-passing air around the heater and into heat exchange relation with the last mentioned condenser portion. 3. In an automobile vehicle heater of the type in which cold air is taken in from the exterior of the vehicle and passed over a heat exchanger prior to delivery to the space to be heated, comprising means for circulating a heating fluid throughv the heat exchanger, .a plenum chamber in the heater upon the 'cold air side of the heat exchanger, ableeder tube extending from said plenum chamber around said exchanger, a valve for controlling the flow of said fluid through the heat exchanger, and a single heat responsive element positioned partially within said bleeder tube and partially within the space to be heated for regulating the degree of opening of said valve.

WALTER V. HOBBS.

Eli-DON D. RANEY. 

